This invention relates to a method for forming a lubricant coat on the surface of a steel material to be forged and a forging device provided with a member for forming such as a lubricant coat.
Recently, automobile, electronic, electric, architectural and other industrial fields increasingly require the reduction in the manufacturing cost of various parts. Consequently, the development of cold forging and warm or hot forging operations are increasingly demanded. Most parts ar made of carbon steel and low alloy steel through cold forging. For the cold forging, a horizontal parts former, a vertical parts former, a vertical press and other devices are available. The vertical press incorporates structure for dropping mineral oil or emulsive lubricant onto the surface of a starting material. The starting material is thus prevented from being burnt in a metal mold during forging.
Stainless steel, bearing steel, heat resisting steel and other materials which are hard to work are easily burnt in a metal mold and have other problems with present methods and devices for forging. Cold and warm forging are only partly used in the manufacture of the parts from such materials, because the dropping of lubricant onto the surface of the material provides insufficient lubricating performance. On the other hand, since such materials have high strength and corrosion-resistance, mass production of the parts from them is highly demanded. An effective lubricant is being developed. This lubricant, however, has problems in practical use. The lubricant needs to be formed into an effective lubricant coat having a constant and optimum thickness on the surface of the material to be useful. An irregularly thick lubricant coat would have variances in its lubricating performance, and would cause problems in the manufacture of the parts having strength and a complicated configuration. In an inline type forging device, a wire rod is cut, conveyed through and forged in multiple metal molds. The inline type forging device requires the development of means for applying lubricant onto the cut end surfaces of the cut pieces of the wire rod.
Consequently, this invention has been developed to enable the cold and warm forging of stainless steel and other materials which are hard to work, to lengthen the durability of the metal molds used for forging, and to forge products with a reduced cost.